Display device having a multi-layered filling pattern

ABSTRACT

A display device includes an organic electroluminescent area on the first base substrate, a second base substrate on the organic electroluminescent area and including a light emitting area and a non-light emitting area, a base layer between the organic electroluminescent area and the second base substrate, a conductive layer between the base layer and the organic electroluminescent area, and a filling pattern between the base layer and the conductive layer and overlapping a portion of the conductive layer. The conductive layer overlaps the light emitting area and the non-light emitting area, covers the filling pattern, and contacts the base layer. A portion of the conductive layer may contact the organic electroluminescent area. The filling pattern includes a first filling pattern having an insulating material and a second filling pattern on the first filling pattern. The second filling pattern has a conductive material with a lower resistance than the conductive layer.

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2015-0151348, filed on Oct. 29, 2015,and entitled, “Display Device and Method for Fabricating the Same,” isincorporated by reference herein in its entirety.

BACKGROUND

1. Field

One or more embodiments described herein relate to a display device anda method for fabricating a display device.

2. Description of the Related Art

A flat display device may be classified as an emissive type or anon-emissive type. Examples of emissive-type displays include flatcathode ray tubes, plasma display panels, and an organic light emittingdisplays. An organic light emitting display is self-emissive with alarge viewing angle, excellent contrast, and fast response time.

Accordingly, organic light emitting displays may be used in mobiledevices, e.g., smartphones, ultra-slim notebook computers, tabletpersonal computers, and flexible display devices. Organic light emittingdisplays may also used in large-scale electronic products, e.g.,ultra-slim televisions.

Organic light emitting displays emit color light based on arecombination of holes and electrons in a light emitting layer locatedbetween an anode and cathode.

SUMMARY

In accordance with one or more embodiments, a display device including afirst base substrate; an organic electroluminescent area on the firstbase substrate; a second base substrate on the organicelectroluminescent area and including a light emitting area and anon-light emitting area; a base layer between the organicelectroluminescent area and the second base substrate; a conductivelayer between the base layer and the organic electroluminescent area;and a filling pattern between the base layer and the conductive layerand overlapping a portion of the conductive layer. The conductive layeroverlaps the light emitting area and the non-light emitting area, coversthe filling pattern, and contacts the base layer, a portion of theconductive layer contacts the organic electroluminescent area, and thefilling pattern includes a first filling pattern including an insulatingmaterial and a second filling pattern on the first filling pattern, thesecond filling pattern including a conductive material having a lowerresistance than the conductive layer. The insulating material mayincludes a photoresist.

The conductive material may include at least one of a metal or a metalalloy. The conductive material may include at least one of aluminum(Al), copper (Cu), or silver (Ag), or includes an alloy thereof. Theconductive layer may include a transparent conductive oxide.

The filling pattern may be spaced apart from the light emitting area andmay overlap the non-light emitting area. The width of the fillingpattern may be less than the width of the non-light emitting area.

The conductive layer may include a first conductive area protruding fromthe base layer toward the first base substrate and accommodating thefilling pattern; and a second conductive area connected to the firstconductive part. At least a portion of the first conductive area maycontact the organic electroluminescent area, and the second conductivearea may be spaced apart from the organic electroluminescent area.

The organic electroluminescent area may include an anode; a lightemitter on the anode to emit white light; and a cathode on the lightemitter, wherein the portion of the conductive layer contacts thecathode. The light emitter may include a first light emitting layer; acharge generating layer on the first light emitting layer; and a secondlight emitting layer on the charge generating layer. The light emittermay include a first light emitting layer; a charge generating layer onthe first light emitting layer; a second light emitting layer on thecharge generating layer; and a third light emitting layer on the secondlight emitting layer and contacting the second light emitting layer. Thelight emitter may include a first light emitting layer; a first chargegenerating layer on the first light emitting layer; a second lightemitting layer on the first charge generating layer; a second chargegenerating layer on the second light emitting layer; and a third lightemitting layer on the second charge generating layer.

The organic electroluminescent area may emit white light. The base layermay include at least one of a color filter layer or an overcoat layer.The base layer may include a color filter layer that has a color filterand a black matrix, at least a portion of the filling patternoverlapping the black matrix.

In accordance with one or more other embodiments, a method forfabricating a display device includes preparing a first base substrateand an organic electroluminescent area on the first base substrate;preparing a second base substrate including a light emitting area and anon-light emitting area; providing a filling pattern on the second basesubstrate; and providing a conductive layer on the second base substrateto cover the filling pattern, wherein providing the filling patternincludes: providing a first layer on the second base substrate, thefirst layer including an insulating material; providing a second layeron the first layer, the second layer including a conductive materialhaving a lower resistance than the conductive layer; patterning thesecond layer; and patterning the first layer, wherein, providing thefilling pattern includes providing the filling pattern to be spacedapart from the light emitting area and to overlap a portion of thenon-light emitting area. Providing the first layer may be performed byapplying at least one of a metal or a metal alloy. Providing the secondlayer may be performed by applying a photoresist. The conductive layermay include a transparent conductive oxide.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail exemplary embodiments with reference to the attached drawingsin which:

FIG. 1 illustrates an embodiment of a display device;

FIG. 2A illustrates an embodiment of a subpixel, FIG. 2B illustrates aplan view of the subpixel, and FIG. 2C illustrates a cross-sectionalview along line I-I′ in FIG. 2B;

FIG. 3A illustrates an embodiment which includes pixels, a fillingpattern, and a conductive layer in a display device, and FIG. 3Billustrates a perspective view corresponding to the embodiment in FIG.3A;

FIGS. 4A to 4D illustrate examples of light emitting areas in a displaydevice;

FIG. 5A illustrates an embodiment of an organic electroluminescentdevice, FIG. 5B illustrates a cross-sectional view along line II-II′ inFIG. 3A, and FIG. 5C illustrates a cross-sectional view along line inFIG. 3A;

FIGS. 6A to 6D illustrate an embodiment of a light emitting unit;

FIGS. 7A and 7B illustrate an example of a positional relationship in afilling pattern in a display device according to one embodiment;

FIG. 8A illustrates an embodiment of a method for fabricating a displaydevice, and FIG. 8B illustrates additional operations of the method; and

FIGS. 9A to 9H illustrate stages of fabrication corresponding to themethod.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey exemplary implementations to those skilled in the art. Theembodiments may be combined to form additional embodiments.

In the drawing figures, the dimensions of layers and regions may beexaggerated for clarity of illustration. It will also be understood thatwhen a layer or element is referred to as being “on” another layer orsubstrate, it can be directly on the other layer or substrate, orintervening layers may also be present. Further, it will be understoodthat when a layer is referred to as being “under” another layer, it canbe directly under, and one or more intervening layers may also bepresent. In addition, it will also be understood that when a layer isreferred to as being “between” two layers, it can be the only layerbetween the two layers, or one or more intervening layers may also bepresent. Like reference numerals refer to like elements throughout.

It will be understood that the terms “includes” and/or “including”, whenused in this specification, specify the presence of stated features,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. Moreover, it will be understood that when a part such as alayer, a film, an area, a plate, etc. is referred to as being “on”another part, it can be “directly on” the other part, or interveningparts may be present. In addition, when a part such as a layer, a film,an area, a plate, etc. is referred to as being “below” another part, itcan be “directly below” the other part, or intervening parts may bepresent.

When an element is referred to as being “connected” or “coupled” toanother element, it can be directly connected or coupled to the anotherelement or be indirectly connected or coupled to the another elementwith one or more intervening elements interposed therebetween. Inaddition, when an element is referred to as “including” a component,this indicates that the element may further include another componentinstead of excluding another component unless there is differentdisclosure.

FIG. 1 illustrates an embodiment of a display device 10 which includes adisplay area DA and a non-display area NDA. The display area DA displaysan image. When viewed from the thickness direction (for example, DR4) ofthe display device 10, the display area DA may have a roughlyrectangular shape or another shape.

The display area DA includes a plurality of pixel areas PA arranged inthe form of a matrix. A plurality of pixels PX are in the pixel areasPA. Each pixel PX includes an organic electroluminescent device or area(e.g., OEL in FIG. 5A) and a plurality of subpixels (e.g., SPX in FIG.2A). Each subpixel may include a sub-organic electroluminescent deviceor area (e.g., S_OEL in FIG. 2A).

The non-display area NDA does not display an image. When viewed from athickness direction (for example, DR4) of the display device, thenon-display area NDA, for example, may surround or otherwise be adjacentto the display area DA. For example, the non-display area NDA may beadjacent to the display area DA in a first direction DR1 and a thirddirection DR3. The third direction DR3 intersects the first directionDR1 and a second direction DR2.

FIG. 2A illustrates an embodiment of a subpixel, which is representativeof the subpixels in the display device 10. FIG. 2B is a plan viewillustrating the subpixel. FIG. 2C illustrates a cross-sectional viewalong line I-I′ in FIG. 2B.

Referring to FIGS. 2A to 2C, the subpixel SPX may be connected to aconductive part including a data line DL and a drive voltage line DVL.The subpixel includes thin film transistors TFT1 and TFT2 connected tothe conductive part. A sub-organic electroluminescent device S_OEL and acapacitor Cst are connected to the thin film transistors TFT1 and TFT2.The subpixel emits light of a specific color, e.g., red, green, blue,cyan, magenta, yellow, white, or another color.

A first voltage ELVDD and a second voltage ELVSS lower than the firstvoltage ELVDD are provided to the subpixel SPX. The first voltage ELVDDand the second voltage ELVSS are provided to the sub-organicelectroluminescent device S_OEL.

A scan line SL extends in the first direction DR1. The data line DLextends in a third direction DR3 intersecting the scan line SL. A drivevoltage line DVL extends in a direction substantially identical to thatof the data line DL, that is, the third direction DR3. The drive voltageline DVL receives the first voltage ELVDD. The scan line SL transmits ascan signal to the thin film transistor TFT1 and TFT2. The data line DLtransmits a data signal to the thin film transistor TFT1 and TFT2. Thedrive voltage line DVL provides a drive voltage to the thin filmtransistor TFT1 and TFT2. A conductive layer CL, a filling pattern FP,and the sub-organic electroluminescent device S_OEL receive the secondvoltage ELVSS.

The thin film transistors TFT1 and TFT2 include a driving thin filmtransistor TFT2 to control the sub-organic electroluminescent deviceS_OEL and a switching thin film transistor TFT1 to switch the drivingthin film transistor TFT2. In an embodiment, the subpixel SPX includestwo of the thin film transistors TFT1 and TFT2. In another embodiment,the subpixel SPX may have a different number of transistors and/orcapacitors.

The switching thin film transistor TFT1 includes a first gate electrodeGE1, a first source electrode SE1, and a first drain electrode DE1. Thefirst gate electrode GE1 is connected to the scan line SL, and the firstsource electrode SE1 is connected to the data line DL. The first drainelectrode DE1 is connected to a first common electrode CE1 through afifth contact hole CH5. The switching thin film transistor TFT1transmits the data signal from the data line DL to the driving thin filmtransistor TFT2 according to the scan signal applied to the scan lineSL.

The driving thin film transistor TFT2 includes a second gate electrodeGE2, a second source electrode SE2, and a second drain electrode DE2.The second gate electrode GE2 is connected to the first common electrodeCE1. The second source electrode SE2 is connected to the drive voltageline DVL. The second drain electrode DE2 is connected to an anode ANthrough a third contact hole CH3.

The capacitor Cst is connected between the second gate electrode GE2 andthe second source electrode SE2, which are in the driving thin filmtransistor TFT2. The capacitor Cst charges and maintains the data signalinput to the second gate electrode GE2 in the driving thin filmtransistor TFT2. The capacitor Cst may include the first commonelectrode CE1 connected to the first drain electrode DE1 through a sixthcontact hole CH6 and a second common electrode CE2 connected to thedrive voltage line DVL.

In accordance with the present embodiment, the display device 10includes a first substrate and a second substrate. The first substrateincludes a first base substrate BS1, the thin film transistor TFT1 andTFT2, and the organic electroluminescent device (e.g., OEL in FIG. 5A).The second substrate includes a second base substrate BS2, a base layerCF1, CF2, CF3, CF4, BM, and OC, the conductive layer CL, and the fillingpattern FP.

The first base substrate BS1 includes a light emitting area and anon-light emitting area. The light emitting area includes a first lightemitting area (e.g., EA1 in FIG. 3A), a second light emitting area(e.g., EA2 in FIG. 3A), a third light emitting area (e.g., EA3 in FIG.3A), and a fourth light emitting area (e.g., EA4 in FIG. 3A). Thenon-light emitting area includes a first non-light emitting area (e.g.,NEA1 in FIG. 3A), a second non-light emitting area (e.g., NEA2 in FIG.3A), a third non-light emitting area (e.g., NEA3 in FIG. 3A), and afourth non-light emitting area (e.g., NEA4 in FIG. 3A).

The first base substrate may include an insulating material such asglass, plastic, or quartz. An organic polymer in the first basesubstrate BS1 may include polyethylene terephthalate (PET), polyethylenenaphthalate (PEN), polyimide, or polyethersulfone. The first basesubstrate BS1 may be selected by considering mechanical strength,thermal stability, transparency, surface smoothness, ease of use, orwater resistance, and the like.

A substrate buffer layer may be disposed on the first base substrateBS1. The substrate buffer layer prevents impurities from diffusing tothe switching thin film transistor TFT1 and the driving thin filmtransistor TFT2. The substrate buffer layer may be formed, for example,of silicon nitride (SiNx), silicon oxide (SiOx), or silicon oxynitride(SiOxNy), and the like, and may also be excluded according to thematerial and process conditions of the first base substrate BS1.

A first semiconductor layer SM1 and a second semiconductor layer SM2 areon the first base substrate BS1. The first semiconductor layer SM1 andthe second semiconductor layer SM2 include a semiconductor material andrespectively act as an activation layer for the switching thin filmtransistor TFT1 and the driving thin film transistor TFT2. Each of thefirst semiconductor layer SM1 and the second semiconductor layer SM2includes a channel area CA between a source area SA and a drain areaDRA. Each of the first semiconductor layer SM1 and the secondsemiconductor layer SM2 may include an inorganic semiconductor materialand/or an organic semiconductor material. The source area SA and thedrain area DRA may be doped with n-type or p-type impurities.

A gate insulating layer GI may be on the first semiconductor layer SM1and the second semiconductor layer SM2.

The gate insulating layer G1 covers the first semiconductor layer SM1and the second semiconductor layer SM2. The gate insulating layer GI mayinclude an organic insulating material or an inorganic insulatingmaterial.

The first gate electrode GE1 and the second gate electrode GE2 are onthe gate insulating layer G1. The first gate electrode GE1 and thesecond gate electrode GE2 are formed to cover areas corresponding to thechannel area CA in the first semiconductor layer SM1 and the secondsemiconductor layer SM2, respectively.

An interlayer insulating layer IL is on the first gate electrode GE1 andthe second gate electrode GE2. The interlayer insulating layer IL coversthe first gate electrode GE1 and the second gate electrode GE2. Theinterlayer insulating layer IL may include an organic insulatingmaterial or an inorganic insulating material.

The first source electrode SE1, the first drain electrode DE1, thesecond source electrode SE2, and the second drain electrode DE2 are onthe interlayer insulating layer IL. The second drain electrode DE2 isconnected to the drain area DRA in the second semiconductor layer SM2through a first contact hole CH1 in the gate insulating layer GI and theinterlayer insulating layer IL. The second source electrode SE2 isconnected to the source area SA in the second semiconductor layer SM2through a second contact hole CH2 in the gate insulating layer GI andthe interlayer insulating layer IL. The first source electrode SE1 isconnected to the source area in the first semiconductor layer SM1through a fourth contact hole CH4 in the gate insulating layer GI andthe interlayer insulating layer IL. The first drain electrode DE1 isconnected to the drain area in the first semiconductor layer SM1 throughthe fifth contact hole CH5 in the gate insulating layer GI and theinterlayer insulating layer IL.

A passivation layer PSL is on the first source electrode SE1 and firstdrain electrode DE1 and on the second source electrode SE2 and seconddrain electrode DE2. The passivation layer PSL may serve as a protectivefilm to protect the switching thin film transistor TFT1 and the drivingthin film transistor TFT2. The passivation layer PSO may also serve asan overcoat film for flattening the top surface thereof.

The anode AN may be on the passivation layer PSL and may be, forexample, a positive electrode. The anode AN is connected to the seconddrain electrode DE2 in the driving thin film transistor TFT2 through thethird contact hole CH3 in the passivation layer PSL.

FIG. 3A illustrating a plurality of pixels PX, the filling pattern, andthe conductive layer in the display device. FIG. 3B is an explodedperspective view corresponding to FIG. 3A.

Referring to FIG. 1, FIGS. 2A to 2C, and FIGS. 3A and 3B, each pixel PXincludes a plurality of subpixels, e.g., a first subpixel SPX1, a secondsubpixel SPX2, a third subpixel SPX3, and a fourth subpixel SPX4. Eachsubpixel SPX includes the light emitting area and the non-light emittingarea. FIGS. 3A and 3B are exemplarily in that, in a plane view in thefirst direction DR1, the first subpixel SPX1 is adjacent to the secondsubpixel SPX2, and the third subpixel SPX3 is adjacent to the fourthsubpixel SPX4. Also, in a plane view in the third direction DR3, thefirst subpixel SPX1 is adjacent to the third subpixel SPX3, and thesecond subpixel SPX2 is adjacent to the fourth subpixel SP4. In anotherembodiment, the first subpixel SPX1, the second subpixel SPX2, the thirdsubpixel SPX3, and the fourth subpixel SPX4 may be arranged in differentways.

Moreover, FIGS. 3A and 3B are exemplarily in that, in a plane view, thefirst subpixel SPX1, the second subpixel SPX2, the third subpixel SPX3,and the fourth subpixel SPX4 are identical in shape to each other andequal in size to each other. In another embodiment, the shape and/orsize of the first subpixel SPX1, the second subpixel SPX2, the thirdsubpixel SPX3, and the fourth subpixel SPX4 may be different.

Furthermore, FIGS. 3A and 3B are exemplarily in that each of the firstsubpixel SPX1, the second subpixel SPX2, the third subpixel SPX3, andthe fourth subpixel SPX4 has a rectangular shape. In another embodiment,the first subpixel SPX1, the second subpixel SPX2, the third subpixelSPX3, and the fourth subpixel SPX4 may a different shape, e.g., at leastone shape among a circle, an ellipse, a square, a parallelogram, atrapezoid, and a rhombus. In addition, each of the first subpixel SPX1,the second subpixel SPX2, the third subpixel SPX3, and the fourthsubpixel SPX4 may, for example, have a rectangular shape in which atleast one corner has a rounded shape.

Referring to FIGS. 3A and 3B, in a plane view, each of the first lightemitting area EA1, the second light emitting area EA2, the third lightemitting area EA3, and the fourth light emitting area EA4 may have arectangular shape. In another embodiment, the first light emitting areaEA1, the second light emitting area EA2, the third light emitting areaEA3, and the fourth light emitting area EA4 may have a different shape,e.g., at least one shape among a circle, an ellipse, a square, aparallelogram, a trapezoid, and a rhombus. Moreover, in a plane view,each of the first light emitting area EA1, the second light emittingarea EA2, the third light emitting area EA3, and the fourth lightemitting area EA4 may, for example, have a rectangular shape in whichone at least one corner has a rounded shape.

Referring to FIGS. 3A and 3B, in a plane view, the first light emittingarea EA1, the second light emitting area EA2, the third light emittingarea EA3, and the fourth light emitting area EA4 may be spaced apart andin sequence in the first direction DR1. In a plane view, the shape ofeach of the first light emitting area EA1, the second light emittingarea EA2, the third light emitting area EA3, and the fourth lightemitting area EA4 may be a rectangle having a length in the thirddirection DR3 longer than the length in the first direction DR1.

The conductive layer CL may overlap each of the light emitting area EA1,EA2, EA3, and EA4 and the non-light emitting area NEA1, NEA2, NEA3, andNEA4. For example, in a plane view, the conductive layer CL may overlapeach of the light emitting area EA1, EA2, EA3, and EA4 and the non-lightemitting area NEA1, NEA2, NEA3, and NEA4.

The filling pattern FP overlaps a portion of the conductive layer CL.The filling pattern FP may be spaced apart from the light emitting areaEA1, EA2, EA3, and EA4 and may overlap a portion of the non-lightemitting area NEA1, NEA2, NEA3, and NEA4. For example, in a plane view,the filling pattern FP may be spaced apart from the light emitting areaEA1, EA2, EA3, and EA4 and overlap a portion of the non-light emittingarea NEA1, NEA2, NEA3, and NEA4. In a plane view, the width W2 of thefilling pattern FP may be less than the width W1 of the non-lightemitting area NEA1, NEA2, NEA3, and NEA4. (The term “width” may be, forexample, in the first direction).

In a plane view, the filling pattern FP may be in the form of a mesh.For example, in a plane view, the filling pattern FP may be in a formwhere, from a first rectangular shape, second rectangular shapes smallerthan the first rectangular shape are excluded from the first rectangularshape.

The filling pattern FP includes a first filling pattern FP1 and a secondfilling pattern FP2. The first filling pattern FP1 may be spaced apartfrom the light emitting area EA1, EA2, EA3, and EA4 and may overlap aportion of the non-light emitting area NEA1, NEA2, NEA3, and NEA4. In aplane view, the width of the first filling pattern FP1 may be less thanthe width W1 of the non-light emitting area NEA1, NEA2, NEA3, and NEA4.

In a plane view, the first filling pattern FP1 may be in the form of amesh. For example, in a plane view, the first filling pattern FP1 may bein a form where, from a first rectangular shape, second rectangularshapes smaller than the first rectangular shape are excluded from thefirst rectangular shape.

The second filling pattern FP2 may be spaced apart from the lightemitting area EA1, EA2, EA3, and EA4 and may overlap a portion of thenon-light emitting area NEA1, NEA2, NEA3, and NEA4. For example, in aplane view, the second filling pattern FP2 may be spaced apart from thelight emitting area EA1, EA2, EA3, and EA4 and may overlap a portion ofthe non-light emitting area NEA1, NEA2, NEA3, and NEA4. In a plane view,the width of the second filling pattern FP2 may be less than the widthW1 of the non-light emitting area NEA1, NEA2, NEA3, and NEA4.

In a plane view, the second filling pattern may be in the form of amesh. For example, in a plane view, the second filling pattern FP2 maybe in a form where, from a first rectangular shape, second rectangularshapes smaller than the first rectangular shape are excluded from thefirst rectangular shape.

In a plane view, the shape of the first filling pattern FP1 may beidentical to the shape of the second filling pattern FP2. In a planeview, the size of the shape of the first filling pattern FP1 may beequal to, or differ from, the size of the shape of the second fillingpattern FP2.

FIGS. 4A to 4D illustrate embodiments of the light emitting areas in thedisplay device. In a plane view, the first light emitting area EA1, thesecond light emitting area EA2, the third light emitting area EA3, andthe fourth light emitting area EA4 may have various predeterminedshapes.

Referring to FIG. 4A, in a plane view, the first light emitting areaEA1, the second light emitting area EA2, the third light emitting areaEA3, and the fourth light emitting area EA4 may be spaced apart, insequence, in the first direction DR1. Also, in a plane view, the shapeof each of the first light emitting area EA1, the second light emittingarea EA2, the third light emitting area EA3, and the fourth lightemitting area EA4 may be a rectangle having a length in the thirddirection DR3 longer than the length in the first direction DR1.

Referring to FIG. 4B, in a plane view, the first light emitting areaEA1, the second light emitting area EA2, the third light emitting areaEA3, and the fourth light emitting area EA4 may be spaced apart, insequence, in the first direction DR1. Also, in a plane view, the shapeof each of the first light emitting area EA1, the second light emittingarea EA2, the third light emitting area EA3, and the fourth lightemitting area EA4 may be a rectangle having a length in the firstdirection DR1 longer than the length in the third direction DR3.

Referring to FIG. 4C, in a plane view, the first light emitting area EA1and the second light emitting area EA2 may be spaced apart in the thirddirection DR3. The third light emitting area EA3 and the fourth lightemitting area EA4 may be spaced apart in the first direction DR1. Theshape of each of the first light emitting area EA1 and the second lightemitting area EA2 may be a rectangle having a length in the firstdirection DR1 longer than the length in the third direction DR3. Theshape of each of the third light emitting area EA3 and the fourth lightemitting area EA4 may be a rectangle having a length in the thirddirection DR3 longer than the length in the first direction DR1.

Referring to FIG. 4D, in a plane view, the first light emitting area EA1and the second light emitting area EA2 may be spaced apart in the firstdirection DR1. The third light emitting area EA3 and the fourth lightemitting area EA4 may be between the first light emitting area EA1 andthe second light emitting area EA2. The third light emitting area EA3and the fourth light emitting area EA4 may be spaced apart in the thirddirection DR3. The shape of each of the first light emitting area EA1and the second light emitting area EA2 may be a rectangle having alength in the third direction DR3 longer than the length in the firstdirection DR1. The shape of each of the third light emitting area EA3and the fourth light emitting area EA4 may be a rectangle having alength in the first direction DR1 longer than the length in the thirddirection DR3.

FIGS. 4A to 4D illustrate examples, in a plane view, the positionalrelationships between the first light emitting area EA1, the secondlight emitting area EA2, the third light emitting area EA3, and thefourth light emitting area EA4, and the shape of each of the first lightemitting area EA1, the second light emitting area EA2, the third lightemitting area EA3, and the fourth light emitting area EA4. The firstlight emitting area EA1, the second light emitting area EA2, the thirdlight emitting area EA3, and the fourth light emitting area EA4 may bearranged in different ways in other embodiments. Also, the first lightemitting area EA1, the second light emitting area EA2, the third lightemitting area EA3, and the fourth light emitting area EA4 may havedifferent shapes in other embodiments.

FIG. 5A is a cross-sectional view illustrating an embodiment of theorganic electroluminescent (OEL) device which may be included in one ormore embodiments of the display device. The OEL may emit white light ora different color of light.

The organic electroluminescent device OEL includes a first sub-organicelectroluminescent device S_OEL1, a second sub-organicelectroluminescent device S_OEL2, a third sub-organic electroluminescentdevice S_OEL3, and a fourth sub-organic electroluminescent deviceS_OEL4. The first sub-organic electroluminescent device S_OEL1, thesecond sub-organic electroluminescent device S_OEL2, the thirdsub-organic electroluminescent device S_OEL3, and the fourth sub-organicelectroluminescent device S_OEL4 are spaced apart from each other incross section.

The first sub-organic electroluminescent device S_OEL1 includes a firstanode AN1, a first hole transport region part HTRP1, a first lightemitting unit part EMUP1, a first electron transport region part ETRP1,and a first cathode part CATP1. The first sub-organic electroluminescentdevice S_OEL1 may include the first light emitting area EA1 and thefirst non-light emitting area NEA1.

The second sub-organic electroluminescent device S_OEL2 includes asecond anode AN2, a second hole transport region part HTRP2, a secondlight emitting unit part EMUP2, a second electron transport region partETRP2, and a second cathode part CATP2. The second sub-organicelectroluminescent device S_OEL2 may include the second light emittingarea EA2 and the second non-light emitting area NEA2.

The third sub-organic electroluminescent device S_OEL3 includes a thirdanode AN3, a third hole transport region part HTRP3, a third lightemitting unit part EMUP3, a third electron transport region part ETRP3,and a third cathode part CATP3. The third sub-organic electroluminescentdevice S_OEL3 may include the third light emitting area EA3 and thethird non-light emitting area NEA3.

The fourth sub-organic electroluminescent device S_OEL4 includes afourth anode AN4, a fourth hole transport region part HTRP4, a fourthlight emitting unit part EMUP4, a fourth electron transport region partETRP4, and a fourth cathode part CATP4. The fourth sub-organicelectroluminescent device S_OEL4 may include the fourth light emittingarea EA4 and the fourth non-light emitting area NEA4.

FIG. 5B is cross-sectional view along line II-II′ in FIG. 3A, and FIG.5C is a cross-sectional view along line in FIG. 3A.

Referring to FIG. 1, FIGS. 2A to 2C, FIGS. 3A and 3B, and FIGS. 5A to5C, the first anode AN1, the second anode AN2, the third anode AN3, andthe fourth anode AN4 are spaced apart from each other in cross section.The first anode AN1, the second anode AN2, the third anode AN3, and thefourth anode AN4 are spaced apart from each. The first anode AN1, thesecond anode AN2, the third anode AN3, and the fourth anode AN4 may bereflective electrodes. When each of the first anode AN1, the secondanode AN2, the third anode AN3, and the fourth anode AN4 is a reflectiveelectrode, each of the first anode AN1, the second anode AN2, the thirdanode AN3, and the fourth anode AN4 may include, for example, silver(Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold(Au), nickel (Ni), neodymium (Nd), iridium (Ir), chrome (Cr), or acombination of metals.

A hole transport region HTR is on the first anode AN1, the second anodeAN2, the third anode AN3, and the fourth anode AN4. The hole transportregion may be a single body (e.g., with a unitary integral construction)disposed in, for example, the first light emitting area EA1, the firstnon-light emitting area NEA1, the second light emitting area EA2, thesecond non-light emitting area NEA2, the third light emitting area EA3,the third non-light emitting area NEA3, the fourth light emitting areaEA4, and the fourth non-light emitting area NEA4.

The hole transport region HTR includes a hole injection layer and a holetransport layer. The hole injection layer and the hole transport layermay be formed as a single layer. The hole injection layer and the holetransport layer may be formed as a single layer and may include adopant, e.g., a p-type dopant. The hole transport region HTR may furtherinclude at least one of a hole buffer layer or a hole blocking layer.

The hole injection layer may include, for example, a phthalocyaninecompound such as copper phthalocyanine, orn,n′-diphenyl-n,n′-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4′-diamine(DNTPD), 4,4′,4″-tris(3-methylphenylphenylamino (m-MTDATA),4,4′4″-tris(n,n-diphenylamino)triphenylamine (TDATA),4,4′,4″-tris{n,-(2-naphthyl)-n-phenylamino}-triphenylamine (2-TNATA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), polyaniline/camphorsulfonicacid (PANI/CSA), or (polyaniline)/poly(4-styrenesulfonate)(PANI/PSS), and the like.

The hole injection layer may further include a charge generatingmaterial in order to improve conductivity. The charge generatingmaterial may be uniformly or non-uniformly distributed in the holeinjection layer. The charge generating material may be, for example, ap-type dopant. At least a portion of the hole injection layer mayinclude the p-type dopant. The p-type dopant may include, for example,one of a quinone derivative, a metal oxide, or a cyano group-containingcompound. For example, a non-limiting example of the p-type dopant mayinclude a quinone derivative such as tetracyanoquinodimethane (TCNQ) or2,3,5,6-tetrafluoro-tetracyanoquinodimethane (F4-TCNQ), or a metal oxidesuch as tungsten oxide or molybdenum oxide.

The hole transport layer is on the hole injection layer. The holetransport layer may include, for example, a carbazole-based derivativesuch as n-phenylcarbazole or polyvinylcarbazole, a fluorine-basedderivative, a triphenylamine-based derivative such asn,n′-bis(3-methylphenyl)-n,n′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD)or 4,4′,4″-tris(n-carbazolyl)triphenylamine (TCTA),n,n′-di(1-naphthyl)-n,n′-diphenylbenzidine (NPB), or4,4′-cyclohexylidene bis[n,n-bis(4-methylphenyl)benzenamine] (TAPC), andthe like, but is not limited thereto.

The hole transport region HTR includes the first hole transport regionpart HTRP1, the second hole transport region part HTRP2, the third holetransport region part HTRP3, the fourth hole transport region partHTRP4, a fifth hole transport region part HTRP5, a sixth hole transportregion part HTRP6, and a seventh hole transport region part HTRP7. Thefirst hole transport region part HTRP1, the fifth hole transport regionpart HTRP5, the second hole transport region part HTRP2, the sixth holetransport region part HTRP6, the third hole transport region part HTRP3,the seventh hole transport region part HTRP7, and the fourth holetransport region part HTRP4 are, for example, connected in sequence as asingle body.

The first hole transport region part HTRP1 is in the first sub-organicelectroluminescent device S_OEL1. The first hole transport region partHTRP1 overlaps the first anode AN1. The second hole transport regionpart HTRP2 is in the second sub-organic electroluminescent deviceS_OEL2. The second hole transport region part HTRP2 overlaps the secondanode AN2. The third hole transport region part HTRP3 is in the thirdsub-organic electroluminescent device S_OEL3. The third hole transportregion part HTRP3 overlaps the third anode AN3. The fourth holetransport region part HTRP4 is in the fourth sub-organicelectroluminescent device S_OEL4. The fourth hole transport region partHTRP4 overlaps the fourth anode AN4. The fifth hole transport regionpart HTRP5 is disposed between the first hole transport region partHTRP1 and the second hole transport region part HTRP2. The sixth holetransport region part HTRP6 is between the second hole transport regionpart HTRP2 and the third hole transport region part HTRP3. The seventhhole transport region part HTRP7 is between the third hole transportregion part HTRP3 and fourth hole transport region part HTRP4.

The light emitting unit is on the hole transport region HTR. The lightemitting unit may be provided as a single body disposed in, for example,the first light emitting area EA1, the first non-light emitting areaNEA1, the second light emitting area EA2, the second non-light emittingarea NEA2, the third light emitting area EA3, the third non-lightemitting area NEA3, the fourth light emitting area EA4, and the fourthnon-light emitting area NEA4. The light emitting unit may emit, forexample, white light.

The light emitting unit EMU includes the first light emitting unit partEMUP1, the second light emitting unit part EMUP2, the third lightemitting unit part EMUP3, the fourth light emitting unit part EMUP4, afifth light emitting unit part EMUP5, a sixth light emitting unit partEMUP6, and a seventh light emitting unit part EMUP7. The first lightemitting unit part EMUP1, the fifth light emitting unit part EMUP5, thesecond light emitting unit part EMUP2, the sixth light emitting unitpart EMUP6, the third light emitting unit part EMUP3, the seventh lightemitting unit part EMUP7, and the fourth light emitting unit part EMUP4are, for example, connected in sequence as a single body.

FIGS. 6A to 6D are cross-sectional views illustrating embodiments of thelight emitting unit in the display device. Referring to FIG. 6A, thelight emitting unit EMU may include a first light emitting layer EML1, acharge generating layer CGL, and a second light emitting layer EML2 thatare laminated in sequence. The first light emitting layer EML1 and thesecond light emitting layer EML2 may emit light having a different colorfrom each other. For example, the first light emitting layer EML1 mayemit yellow light, and the second light emitting layer EML2 may emitblue light. In another embodiment, the first light emitting layer EML1may emit blue light and the second light emitting layer EML2 may emityellow light.

The charge generating layer CGL is between the first light emittinglayer EML1 and the second light emitting layer EML2 to regulate thecharge uniformity between the first light emitting layer EML1 and thesecond light emitting layer EML2. The charge generating layer CGL mayinclude an interconnecting metal layer to facilitate injection ofelectrons into the first light emitting layer EML1, and aninterconnecting hole injection layer to facilitate injection of holesinto the second light emitting layer EML2.

For example, the interconnecting metal layer may be formed of an organicmaterial layer doped with an alkali metal having excellent electroninjection properties. The interconnecting hole injection layer may eformed of an organic semiconductor layer that includes a p-type organicmaterial. In another embodiment, the charge generating layer CGL may beformed as a single layer.

Referring to FIG. 6B, the light emitting unit EMU may include the firstlight emitting layer EML1, the charge generating layer CGL, the secondlight emitting layer EML2, and a third light emitting layer EML3 thatare laminated in sequence. Each of the first light emitting layer EML1,the second light emitting layer EML2, and the third light emitting layerEML3 may emit light of a different color. For example, the first lightemitting layer EML1 may emit yellow light, the second light emittinglayer EML2 may emit green light, and the third light emitting layer EML3may emit red light. In another embodiment, the first light emittinglayer EML1 may emit yellow light, the second light emitting layer EML2may emit red light, and the third light emitting layer EML3 may emitgreen light. The charge generating layer CGL is between the first lightemitting layer EML1 and the second light emitting layer EML2 to regulatethe charge uniformity between the first light emitting layer EML1 andthe second and third light emitting layers EML2 and EML3.

Referring to FIG. 6C, the light emitting unit EMU may include the firstlight emitting layer EML1, the second light emitting layer EML2, thecharge generating layer CGL, and the third light emitting layer EML3that are laminated in sequence. Each of the first light emitting layerEML1, the second light emitting layer EML2, and the third light emittinglayer EML3 may emit light of a different color. For example, the firstlight emitting layer EML1 may emit red light, the second light emittinglayer EML2 may emit green light, and the third light emitting layer EML3may emit yellow light. In another embodiment, the first light emittinglayer EML1 may emit green light, the second light emitting layer EML2may emit red light, and the third light emitting layer EML3 may emityellow light. The charge generating layer CGL is between the secondlight emitting layer EML2 and the third light emitting layer EML3 andregulates the charge uniformity between the third light emitting layerEML3 and the first and second light emitting layers EML1 and EML2.

Referring to FIG. 6D, the light emitting unit EMU may include the firstlight emitting layer EML1, a first charge generating layer CGL1, thesecond light emitting layer EML2, a second charge generating layer CGL2,and the third light emitting layer EML3 that are laminated in sequence.Each of the first light emitting layer EML1, the second light emittinglayer EML2, and the third light emitting layer EML3 may emit light of adifferent color. For example, one of the layers among the first lightemitting layer EML1, the second light emitting layer EML2, and the thirdlight emitting layer EML3 may emit blue light, one of the remaining mayemit green light, and the other one may emit red light. The first chargegenerating layer CGL1 is between the first light emitting layer EML1 andthe second light emitting layer EML2 and regulates the charge uniformitybetween the first light emitting layer EML1 and the second lightemitting layer EML2. The second charge generating layer CGL2 is betweenthe second light emitting layer EML2 and the third light emitting layerEML3 and regulates the charge uniformity between the second lightemitting layer EML2 and the third light emitting layer EML3.

Referring to FIG. 1, FIGS. 2A to 2C, FIGS. 3A and 3B, and FIGS. 5A to5C, the electron transport region ETR is on the light emitting unit EMU.The electron transport region ETR may be provided as a single body in,for example, the first light emitting area EA1, the first non-lightemitting area NEA1, the second light emitting area EA2, the secondnon-light emitting area NEA2, the third light emitting area EA3, thethird non-light emitting area NEA3, the fourth light emitting area EA4,and the fourth non-light emitting area NEA4. The electron transportregion ETR may further include an electron transport layer. An electroninjection layer is on the electron transport layer. In one embodiment,the electron injection layer may be excluded.

The electron transport layer may include, for example,tris(8-hydroxyquinolinato)aluminum (Alq3),1,3,5-tri(1-phenyl-1h-benzo[d]imidazol-2-yl)phenyl (TPBi),2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP),4,7-diphenyl-1,10-phenanthroline (Bphen),3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ),4-(naphthalen-1-yl)-3,5-diphenyl-4h-1,2,4-triazole (NTAZ),2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD),bis(2-methyl-8-quinolinolato-n1,o8)-(1,1′-biphenyl-4-olato)aluminum(BAlq), berylliumbis(benzoquinolin-10-olate) (Bebq2),9,10-di(naphthalene-2-yl)anthracene (ADN), or derivatives thereof, butis not limited thereto. The thickness of the electron transport layermay be about 100 Å to about 1000 Å, for example about 150 Å to about 500Å. When the thickness of the electron transport layer satisfies such arange, a satisfactory level of the electron transporting property may berealized without a substantial increase in the drive voltage.

The electron injection layer may include, for example, lithium fluoride(LiF), lithium quinolate (LiQ), lithium oxide (Li₂O), sodium chloride(NaCl), cesium fluoride (CsF), a lanthanide metal such as ytterbium(Yb), or a metal halide such as rubidium chloride (RbCl) or rubidiumiodide (RbI). The electron injection layer may include a material inwhich an electron transport material is mixed with an insulating organometal salt. The organo metal salt may be a material having an energyband gap larger than about 4 eV. For example, the organo metal salt mayinclude metal acetate, metal benzoate, metal acetoacetate, metalacetylacetonate, or metal stearate. The thickness of the electroninjection layer may be about 1 Å to about 100 Å, or about 3 Å to about90 Å. When the thickness of the electron injection layer satisfies sucha range, a satisfactory level of the electron injecting property may berealized without a substantial increase in the drive voltage.

The electron transport region ETR includes the first electron transportregion part ETRP1, the second electron transport region part ETRP2, thethird electron transport region part ETRP3, the fourth electrontransport region part ETRP4, a fifth electron transport region partETRP5, a sixth electron transport region part ETRP6, and a seventhelectron transport region part ETRP7. The first electron transportregion part ETRP1, the fifth electron transport region part ETRP5, thesecond electron transport region part ETRP2, the sixth electrontransport region part ETRP6, the third electron transport region partETRP3, the seventh electron transport region part ETRP7, and the fourthelectron transport region part ETRP4 are, for example, connected insequence as a single body.

The first electron transport region part ETRP1 is in the firstsub-organic electroluminescent device S_OEL1. The first electrontransport region part ETRP1 overlaps the first anode AN1, the first holetransport region part HTRP1, and the first light emitting unit partEMUP1. The second electron transport region part ETRP2 is in the secondsub-organic electroluminescent device S_OEL2. The second electrontransport region part ETRP2 overlaps the second anode AN2, the secondhole transport region part HTRP2, and the second light emitting unitpart EMUP2. The third electron transport region part ETRP3 is in thethird sub-organic electroluminescent device S_OEL3. The third electrontransport region part ETRP3 overlaps the third anode AN3, the third holetransport region part HTRP3, and the third light emitting unit partEMUP3. The fourth electron transport region part ETRP4 is in the fourthsub-organic electroluminescent device S_OEL4. The fourth electrontransport region part ETRP4 overlaps the fourth anode AN4, the fourthhole transport region part HTRP4, and the fourth light emitting unitpart EMUP4.

A cathode CAT is on the electron transport region ETR. The cathode maybe provided as a single body in, for example, the first light emittingarea EA1, the first non-light emitting area NEA1, the second lightemitting area EA2, the second non-light emitting area NEA2, the thirdlight emitting area EA3, the third non-light emitting area NEA3, thefourth light emitting area EA4, and the fourth non-light emitting areaNEA4.

The cathode CAT may be a common electrode or a negative electrode. Thecathode CAT may be a semi-transmissive electrode or a reflectiveelectrode. When the cathode CAT is a semi-transmissive electrode or areflective electrode, the cathode CAT may include, for example, silver(Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt),palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir),chrome (Cr), lithium (Li), calcium (Ca), lithium fluoride/calcium(LiF/Ca), lithium fluoride/aluminum (LiF/Al), molybdenum (Mo), titanium(Ti), or compounds or mixtures thereof (for example, a mixture of Ag andMg).

Moreover, the cathode CAT may be a multilayered structure including areflective film or a semi-transmissive film formed of the above suchmaterials, or a transparent conductive film formed of indium tin oxide(ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zincoxide (ITZO), and the like.

The cathode EL2 may be connected to an auxiliary electrode. In order toface toward the light emitting unit, the auxiliary electrode may includea film formed through deposition of, for example, silver (Ag), magnesium(Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold(Au), nickel (Ni), neodymium (Nd), iridium (Ir), chrome (Cr), lithium(Li), calcium (Ca), lithium fluoride/calcium (LiF/Ca), lithiumfluoride/aluminum (LiF/Al), molybdenum (Mo), titanium (Ti), or compoundsor mixtures thereof. The cathode EL2 may include a transparent metaloxide, e.g., indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide(ZnO), indium tin zinc oxide (ITZO), molybdenum (Mo), or titanium (Ti),and the like, disposed on the film.

The organic electroluminescent device OEL may be a front surface lightemitting type. The front surface light emitting type may indicate thatan image is emitted from the first base substrate BS1 toward the secondbase substrate BS2. When the organic electroluminescent device OEL isthe front surface light emitting type, the first anode AN1, the secondanode AN2, the third anode AN3, and the fourth anode AN4 may bereflective electrodes, and the cathode CAT may be a transmissive orsemi-transmissive electrode.

The cathode CAT includes the first cathode part CATP1, the secondcathode part CATP2, the third cathode part CATP3, the fourth cathodepart CATP4, a fifth cathode part CATP5, a sixth cathode part CATP6, anda seventh cathode part CATP7. The first cathode part CATP1, the fifthcathode part CATP5, the second cathode part CATP2, the sixth cathodepart CATP6, the third cathode part CATP3, the seventh cathode partCATP7, and the fourth cathode part CATP4 are, for example, connected insequence as a single body.

In the organic electroluminescent device OEL, when a voltage is appliedto each of the first anode AN1, the second anode AN2, the third anodeAN3, and the fourth anode AN4, and the cathode CAT, holes injected fromthe first anode AN1, the second anode AN2, the third anode AN3, and thefourth anode AN4 passes through the hole transport region HTR and moveto the light emitting unit EMU. Electrons injected from the cathode CATpass through the electron transport region ETR and move to the lightemitting unit EMU. The electrons and holes recombine in the lightemitting unit EMU to generate excitons. Light is emitted when theexcitons fall from an excited state to ground state.

An organic capping layer may be disposed on the cathode CAT. The organiccapping layer may be provided as a single body in, for example, thefirst light emitting area EA1, the first non-light emitting area NEA1,the second light emitting area EA2, the second non-light emitting areaNEA2, the third light emitting area EA3, the third non-light emittingarea NEA3, the fourth light emitting area EA4, and the fourth non-lightemitting area NEA4.

The organic capping layer may reflect, from the top surface of theorganic capping layer toward the light emitting unit EMU, light emittedfrom the light emitting unit EMU. The reflected light is amplified by aresonance effect in the organic layer. Thus, the luminous efficiency ofthe display device 10 may be increased. In the front surface lightemitting type organic electroluminescent device, the organic cappinglayer may prevent loss of light in the cathode CAT through totalinternal reflection of the light.

The organic capping layer may include, for example, at least one ofn4,n4,n4′,n4′-tetra (biphenyl-4-yl) biphenyl-4,4′-diamine (TPD15),4,4′,4″-tris (carbazol sol-9-yl) triphenylamine (TCTA), n, n′-bis(naphthalen-1-yl), or n, n′-bis (phenyl)-2,2′-dimethylbenzidine (α-NPD).

A packaging layer may be provided on the cathode CAT and may be a singlebody in, for example, the first light emitting area EA1, the firstnon-light emitting area NEA1, the second light emitting area EA2, thesecond non-light emitting area NEA2, the third light emitting area EA3,the third non-light emitting area NEA3, the fourth light emitting areaEA4, and the fourth non-light emitting area NEA4.

The packaging layer may cover the cathode CAT and may include at leastone layer of a hybrid layer that includes all of an organic layer, aninorganic layer, an organic material, or an inorganic material. Thepackaging layer may be a single layer or a plurality of layers. Thepackaging layer may be, for example, a thin film packaging layer. Thepackaging layer may serve to protect organic electroluminescent deviceOEL.

The second base substrate BS2 is on the organic electroluminescentdevice OEL. The second base substrate BS2 includes the light emittingarea EA1, EA2, EA3, and EA4 and the non-light emitting area NEA1, NEA2,NEA3, and NEA4. The light emitting area EA1, EA2, EA3, and EA4 includesthe first light emitting area EA1, the second light emitting area EA2,the third light emitting area EA3, and the fourth light emitting areaEA4. The non-light emitting area NEA1, NEA2, NEA3, and NEA4 includes thefirst non-light emitting area NEA1, the second non-light emitting areaNEA2, the third non-light emitting area NEA3, and fourth non-lightemitting area NEA4.

The typical second base substrate BS2 may include, for example, of aninsulating material such as glass, plastic, or quartz. An organicpolymer in the second base substrate BS2 may include, for example,polyethylene terephthalate (PET), polyethylene naphthalate (PEN),polyimide, or polyethersulfone. The second base substrate BS1 may beselected by considering, for example, mechanical strength, thermalstability, transparency, surface smoothness, ease of use, or waterresistance, and the like.

The conductive layer CL, the filling pattern FP, and the base layer arebetween the organic electroluminescent device OEL and the second basesubstrate BS2. The base layer contacts the bottom surface of the basesubstrate BS2 and may include at least one of a color filter layer CF1,CF2, CF3, CF4, and BM or an overcoat layer OC. The color filter layerincludes a color filter CF1, CF2, CF3, and CF4 and a black matrix BM.

The conductive layer CL may be completely disposed between the firstbase substrate BS1 and the second base substrate BS2. The conductivelayer CL contacts the bottom surface of the base layer CF1, CF2, CF3,CF4, BM, and OC. The conductive layer CL is connected to the organicelectroluminescent device OEL. For example, the conductive layer CL isconnected to the cathode CAT.

The conductive layer CL may include a transparent conductive oxide. Thetypical conductive layer CL may include, for example, at least one ofindium tin oxide (ITO), indium zinc oxide (IZO), or indium gallium zincoxide (IGZO).

The conductive layer CL includes a first conductive part CLP1 and asecond conductive part CPLP2. The first conductive part CLP1 protrudesfrom the base layer CF1, CF2, CF3, CF4, BM, and OM toward the first basesubstrate BS1 to accommodate the filling pattern FP. At least a portionof the first conductive part CLP1 contacts the organicelectroluminescent device OEL. For example, at least a portion of thefirst conductive part CLP1 contacts the cathode CAT. In a plane view,the first conductive part CLP1 overlaps at least a portion of the blackmatrix BM. The second conductive part CLP2 is connected to the firstconductive part CLP1. The second conductive part CLP2 is spaced apartfrom the organic electroluminescent device OEL.

As discussed above, the color filter layer CF1, CF2, CF3, CF4, and BMmay be between the conductive layer CL and the second base substrateBS2. The color filter layer CF1, CF2, CF3, CF4, and BM includes thecolor filter CF1, CF2, CF3, CF4 and the black matrix BM. The colorfilter CF1, CF2, CF3, CF4 provides color to light received from thelight emitting unit EMU. The color filter CF1, CF2, CF3, and CF4 mayinclude a first color filter CF1, a second color filter CF2, a thirdcolor filter CF3, and a fourth color filter CF4.

The first color filter CF1 overlaps the first sub-organicelectroluminescent device S_OEL1. The first color filter CF1 is in thefirst light emitting area EA1. The first color filter CF1 may provide,for example, a red color to the light received from the light emittingunit EMU. In one embodiment, the first color filter CF1 may provide adifferent color.

The second color filter CF2 overlaps the second sub-organicelectroluminescent device S_OEL2. The second color filter CF2 is in thesecond light emitting area EA2. The second color filter CF2 may provide,for example, a green color to the light received from the light emittingunit EMU. In another embodiment, the second color filter CF2 may providea different color.

The third color filter CF3 overlaps the third sub-organicelectroluminescent device S_OEL3. The third color filter CF3 is in thethird light emitting area EA3. The third color filter CF3 may provide,for example, a blue color to the light received from the light emittingunit EMU. In another embodiment, the third color filter CF3 may providea different color.

The fourth color filter CF4 overlaps the fourth sub-organicelectroluminescent device S_OEL4. The fourth color filter CF4 is in thefourth light emitting area EA4. The fourth color filter CF4 may provide,for example, a yellow color to the light received from the lightemitting unit EMU. In another embodiment, the fourth color filter CF4may provide a different color.

In FIG. 5B, the color filter was illustrated to include the first colorfilter CF1, the second color filter CF2, the third color filter CF3, andthe fourth color filter CF4. In another embodiment, at least one of thefirst color filter CF1, the second color filter CF2, the third colorfilter CF3, or the fourth color filter CF4 may be excluded. The lightemitting area EA1, EA2, EA3, and EA4 that excludes the color filter CF1,CF2, CF3, and CF4 may emit, for example, white light.

The black matrix BM absorbs light emitted from the light emitting unitEMU. The black matrix BM may overlap a light shielding areacorresponding to an area including the scan line, the data line, and thethin film transistor (e.g., TFT1 and TFT2 in FIG. 2A). The black matrixBM may absorb light to thereby block leakage of light that occurs in thelight shielding area.

The overcoat layer OC may be between the conductive layer CL and thecolor filter CF1, CF2, CF3, CF4, and BM. In one embodiment, the overcoatlayer OC may be excluded. The overcoat layer OC may include at least onelayer of a hybrid layer that includes all of an organic layer, aninorganic layer, an organic material, and an inorganic material. Theovercoat layer OC may be a single layer or a plurality of layers.

The filling pattern FP is between the second base substrate BS2 and theconductive layer CL. The filling pattern FP includes the first fillingpattern FP1 and the second filling pattern FP2. The first fillingpattern FP1 contacts the conductive layer CL. For example, the topsurface of the first filling pattern FP1 contacts the second fillingpattern FP2, and the bottom surface and side wall of the first fillingpattern FP1 contact the conductive layer CL. The first filling patternFP1 includes an insulating material, e.g., a photoresist.

The second filling pattern FP2 is on the first filling pattern FP1 andmay contact the base layer CF1, CF2, CF3, CF4, BM, and OC. For example,the top surface of the second filling pattern FP2 may contact the baselayer CF1, CF2, CF3, CF4, BM, and OC. The bottom surface of the secondfilling pattern FP2 may contact the first filling pattern FP1. The sidewall of the second filling pattern FP2 may contact conductive layer CL.

The second filling pattern FP2 includes a conductive material, forexample, which has a lower electrical resistance than the resistance ofthe conductive layer CL. The conductive material may include at leastone of a metal or a metal alloy. The conductive material may include,for example, at least one of Al, Cu, or Ag, or an alloy thereof. Theresistivity of the conductive material may be, for example, about1.0×10⁻⁸ Ωm to about 30.0×10⁻⁸ Ωm. The resistivity indicates theresistance value when the conductive material has a unit area of 1 m²and a unit length of 1 m.

The conductive layer CL and the filling pattern FP may maintain a cellgap. The cell gap may correspond to the distance between the first basesubstrate BS1 and the second base substrate BS2. For example, in oneembodiment, the cell gap may correspond to the distance between thecathode CAT and the base layer CF1, CF2, CF3, CF4, BM, and OC.

A spacing part GA is between the cathode CAT and the base layer CF1,CF2, CF3, CF4, BM, and OC. The spacing part GA may be in the cell gapand, for example, may be a vacuum layer. In another embodiment, thespacing part GA may be at least one layer of a hybrid layer thatincludes all of an organic layer, an inorganic layer, an organicmaterial, and an inorganic material. The spacing part GA may betransparent.

FIGS. 7A and 7B illustrate examples of the positional relationship inthe filling pattern in the display device. Referring to FIG. 7A, thefilling pattern FP may include first filling pattern lines FPL1 thatextend in the third direction DR3 and which are spaced apart in thefirst direction DR1. Referring to FIG. 7B, the filling pattern FP mayinclude second filling pattern lines FPL2 that extend in the firstdirection DR1 and which are spaced apart in the third direction DR3.

In FIGS. 7A and 7B, in a plane view, the first filling pattern linesFPL1 and the second filling pattern lines FPL2 are spaced apart atconstant intervals. In another embodiment, in a plane view, the firstfilling pattern lines FPL1 and the second filling pattern lines FPL2 maybe at random intervals. Moreover, FIGS. 7A and 7B, in a plane view,illustrate the positional relationship in the filling pattern FP. Inanother embodiment, the filling pattern may be disposed (e.g., randomlydisposed) in a plane view in the non-light emitting area NEA1, NEA2,NEA3, and NEA4.

One type of display device may include a spacer for maintaining the cellgap between the first base substrate and the second base substrate. Inaccordance with one embodiment, instead of the separate cell gap, thedisplay device may include the filling pattern and the conductive layerto maintain the cell gap between the first base substrate and the secondbase substrate. Since the display device according to at least oneembodiment does not require a separate process for providing the spacer,the fabrication process may be simplified.

Moreover, in one type of front surface light emitting type displaydevice that has been proposed, light passes from the light emitting unitthrough the cathode and thus may be perceived by a user. The cathode maybe a conductive material that is transmissive or semi-transmissive. Thetransmissive or semi-transmissive material has a thin thickness.Consequently, the cathode may have an elevated resistance. Accordingly,there is a limitation in that a voltage drop (IR drop) occurs in thecathode.

In accordance with one or more embodiments, the filling pattern isconnected to the conductive layer and the cathode and includes aconductive material having a lower resistance than the conductive layer.Thus, the resistance of the cathode may be reduced. As a result, anyvoltage drop that may occur in the cathode of the display device may bereduced or prevented. Also, the conductive layer and the filling patternmay maintain a uniform voltage distribution of the cathode, and powerconsumption for driving the display device may be reduced. As a result,the display device according to the present embodiment may have a highlight emitting efficiency. Moreover, even when the cathode has a largearea, uniform display quality may be realized over the entire surface.

FIG. 8A illustrates an embodiment of a method for fabricating thedisplay device. FIG. 8B illustrates additional operations of the method.

Referring to FIGS. 5A to 5C, and FIG. 8A, the method includes preparingthe first base substrate BS1 and the organic electroluminescent deviceon the first base substrate BS1 (operation S100), preparing the secondbase substrate BS2 divided into the light emitting area EA1, EA2, EA3,and EA4 and the non-light emitting area NEA1, NEA2, NEA3, and NEA4(operation S200), providing the filling pattern FP on the secondsubstrate BS2 (operation S300), and providing the conductive layer CL onthe second base substrate BS2 to cover the filling pattern FP (operationS400).

Operation S300 for providing the filling pattern FP may includeproviding on the second base substrate BS2 a first layer L1 thatincludes an insulating material (operation S310), providing a secondlayer L2 on the first layer L1 that includes a conductive materialhaving a lower resistance than the resistance of the conductive layer CL(operation S320), patterning the second layer L2 (operation S3300), andpatterning the first layer L1 (operation S340).

FIGS. 9A to 9H illustrate, in sequence, operations included in oneembodiment of a method for fabricating a display device. Referring toFIGS. 8A, 8B, and 9A, the method includes preparing the second basesubstrate BS2. Referring to FIGS. 8A, 8B, and 9B, the color filter layerCF1, CF2, and BM is provided on the second base substrate BS2. The colorfilter CF1, CF2, and BM includes the color filter CF1 and CF2 and theblack matrix BM. In FIG. 9B, for ease of description, only the firstcolor filter CF1 and the second color filter CF2 are illustrated.

Referring to FIGS. 8A, 8B, and 9C, the overcoat layer OC is provided onthe color filter layer CF1, CF2, and BM. In another embodiment, at leastone operation may be excluded among the operations of providing thecolor filter CF1, CF2, and BM and providing the overcoat layer OC.

Referring to FIGS. 8A, 8B, and 9D, the first layer L1 is provided on thecolor filter layer CF1, CF2, and BM (S310). The operation S310 ofproviding the first layer L1 may be performed, for example, by applyingat least one of a metal of a metal alloy.

Referring to FIGS. 8A, 8B, and 9E, the second layer L2 is provided onthe first layer L1 (S320). The operation of providing the second layerL2 may be performed, for example, by applying a photoresist.

Referring to FIGS. 3A, 3B, 8A, 8B, and 9F, the second layer L2 ispatterned (S330). By patterning the second layer L2, the first fillingpattern FP1 may be provided. The second layer L2 may be etched using,for example, a mask.

Referring to FIGS. 3A, 3B, 8A, 8B, and 9G, the first layer L1 ispatterned (S340). By patterning the first layer L1, the second fillingpattern FP2 may be provided. The first layer L1 may be etched using, forexample, first filling pattern FP1 as a mask.

The filling pattern FP includes the first filling pattern FP1 and thesecond filling pattern FP2. The first filling pattern FP1 may be spacedapart from the light emitting area EA1, EA2, EA3, and EA4 and overlap aportion of the non-light emitting area NEA1, NEA2, NEA3, and NEA4. Forexample, in a plane view, the first filling pattern FP1 may be spacedapart from the light emitting area EA1, EA2, EA3, and EA4 and overlap aportion of the non-light emitting area NEA1, NEA2, NEA3, and NEA4. In aplane view, the width of the first filling pattern FP1 may be less thanthe width W1 of the non-light emitting area NEA1, NEA2, NEA3, and NEA4.

The second filling pattern FP2 may be spaced apart from the lightemitting area EA1, EA2, EA3, and EA4 and overlap a portion of thenon-light emitting area NEA1, NEA2, NEA3, and NEA4. For example, in aplane view, the second filling pattern FP2 may be spaced apart from thelight emitting area EA1, EA2, EA3, and EA4 and overlap a portion of thenon-light emitting area NEA1, NEA2, NEA3, and NEA4. In a plane view, thewidth of the second filling pattern FP2 may be less than the width W1 ofthe non-light emitting area NEA1, NEA2, NEA3, and NEA4.

Referring to FIGS. 3A, 3B, 8A, 8B, and 9H, the conductive layer CL maybe provided on the filling pattern FP, that was provided by patterningeach of the first layer L1 and the second layer L2 S400. In operationS400 of providing the conductive layer CL, the conductive layer CL mayinclude a transparent conductive oxide.

The conductive layer CL may overlap each of the light emitting area EA1,EA2, EA3, and EA4 and the non-light emitting area NEA1, NEA2, NEA3, andNEA4. For example, in a plane view, the conductive layer CL may overlapeach of the light emitting area EA1, EA2, EA3, and EA4 and the non-lightemitting area NEA1, NEA2, NEA3, and NEA4.

One proposed method for fabricating a display device includes providinga spacer to maintain a cell gap between the first base substrate and thesecond base substrate. However, in accordance with at least oneembodiment, the method of the present embodiment includes the fillingpattern and the conductive layer instead of the separate cell gap. Thefilling pattern and the conductive layer may maintain the cell gapbetween the first and second base substrates. Thus, the method forfabricating a display device according to the present embodiment doesnot require a separate process for providing the spacer. As a result,the fabrication process may be simplified.

Moreover, since the filling pattern in the present embodiment isconnected to the conductive layer and the cathode and includes theconductive material having a lower resistance than the conductive layer,the resistance of the cathode may be reduced. As a result, the voltagedrop that otherwise may occur in the cathode of the display device maybe prevented, and the conductive layer and the filling pattern maymaintain the uniform voltage distribution of the cathode. Therefore, thepower consumption for driving the display device according at least oneembodiment may be reduced and light emitting efficiency may be enhanced.Moreover, even when the cathode is formed to have a large area, auniform display quality may be realized over the entire surface.

In accordance with one or more embodiments, a display device is providedin which a voltage drop in a cathode may be prevented and light emittingefficiency may be improved. Also, fabrication method is provided whichprevents a voltage drop from occurring in a cathode, thereby allowingfor improved light emitting efficiency and simplifying the fabricationprocess.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of skill in the art as of thefiling of the present application, features, characteristics, and/orelements described in connection with a particular embodiment may beused singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwiseindicated. Accordingly, it will be understood by those of skill in theart that various changes in form and details may be made withoutdeparting from the spirit and scope of the present embodiment set forthin the claims.

What is claimed is:
 1. A display device, comprising: a first basesubstrate; an organic electroluminescent device on the first basesubstrate; a second base substrate on the organic electroluminescentdevice and including a light emitting area and a non-light emittingarea; a base layer between the organic electroluminescent device and thesecond base substrate; a conductive layer between the base layer and theorganic electroluminescent device; and a filling pattern between thebase layer and the conductive layer and overlapping a portion of theconductive layer, wherein: the conductive layer overlaps the lightemitting area and the non-light emitting area, covers the fillingpattern, and contacts the base layer, a portion of the conductive layercontacts the organic electroluminescent device, and the filling patternincludes a first filling pattern including an insulating material and asecond filling pattern on the first filling pattern, the second fillingpattern including a conductive material having a lower resistance thanthe conductive layer.
 2. The display device as claimed in claim 1,wherein the insulating material includes a photoresist.
 3. The displaydevice as claimed in claim 1, wherein the conductive material includesat least one of a metal or a metal alloy.
 4. The display device asclaimed in claim 1, wherein the conductive material includes at leastone of aluminum (Al), copper (Cu), or silver (Ag), or includes an alloythereof.
 5. The display device as claimed in claim 1, wherein theconductive layer includes a transparent conductive oxide.
 6. The displaydevice as claimed in claim 1, wherein the filling pattern is spacedapart from the light emitting area and overlaps the non-light emittingarea.
 7. The display device as claimed in claim 1, wherein the width ofthe filling pattern is less than the width of the non-light emittingarea.
 8. The display device as claimed in claim 1, wherein theconductive layer includes: a first conductive area protruding from thebase layer toward the first base substrate and accommodating the fillingpattern; and a second conductive area connected to the first conductivepart.
 9. The display device as claimed in claim 8, wherein: at least aportion of the first conductive area contacts the organicelectroluminescent device, and the second conductive area is spacedapart from the organic electroluminescent device.
 10. The display deviceas claimed in claim 1, wherein the organic electroluminescent deviceincludes: an anode; a light emitter on the anode to emit white light;and a cathode on the light emitter, wherein the portion of theconductive layer contacts the cathode.
 11. The display device as claimedin claim 10, wherein the light emitter includes: a first light emittinglayer; a charge generating layer on the first light emitting layer; anda second light emitting layer on the charge generating layer.
 12. Thedisplay device as claimed in claim 10, wherein the light emitterincludes: a first light emitting layer; a charge generating layer on thefirst light emitting layer; a second light emitting layer on the chargegenerating layer; and a third light emitting layer on the second lightemitting layer and contacting the second light emitting layer.
 13. Thedisplay device as claimed in claim 10, wherein the light emitterincludes: a first light emitting layer; a first charge generating layeron the first light emitting layer; a second light emitting layer on thefirst charge generating layer; a second charge generating layer on thesecond light emitting layer; and a third light emitting layer on thesecond charge generating layer.
 14. The display device as claimed inclaim 1, wherein the organic electroluminescent device emits whitelight.
 15. The display device as claimed in claim 1, wherein the baselayer includes at least one of a color filter layer or an overcoatlayer.
 16. The display device as claimed in claim 1, wherein the baselayer includes a color filter layer that has a color filter and a blackmatrix, at least a portion of the filling pattern overlapping the blackmatrix.